%%This is a very basic article template.
%%There is just one section and two subsections.
\documentclass{article}

\usepackage{tikz}
\usetikzlibrary{shapes,positioning,fit}

\begin{document}
\begin{tikzpicture}

\tikzstyle{box} = [
	draw,
	rectangle,
	rounded corners,
	minimum height=20pt,
	fill=white,
	fill opacity=0.5,
	text opacity=1
]
\node[
	draw,
	ellipse,
	minimum width=200pt,
	minimum height=100pt,
	line width=10pt,
	color=black!20
](ell1) {};
\node[
	box,
	minimum width=30pt
](new-case) at (ell1.north west) { New case};
\node[
	box,
	minimum width=40pt
](similar-cases) at (ell1.north east) {};
\node[
	box,
	minimum width=40pt,
	yshift=-2pt,
	xshift=-2pt
](similar-cases-bis) at (similar-cases) {};
\node[
	below=0pt of similar-cases-bis.north
](similar-cases-label-1) {Similar};
\node[
	above=0pt of similar-cases-bis.south
](similar-cases-label-2) {cases};
\node[
	box,
	right=10pt of similar-cases
](new-case-2) {New case};
\node[
	box,
	minimum width=30pt
](solved-case) at (ell1.south east) {Solved case};
\node[
	box,
	minimum width=30pt
](revised-case) at (ell1.south west) {Revised case};
\node[
	below=-2pt of ell1.north
](retrieve) {Retrieve};
\node[
	above=-2pt of ell1.south
](revise) {Revise};
\node[
	rotate=-90,
	yshift=-6pt
](reuse) at (ell1.east) {Reuse};
\node[
	rotate=90,
	yshift=-6pt
](retain) at (ell1.west) {Retain};
\node [
	cloud, 
	draw,
	cloud 
	puffs=10,
	cloud puff arc=120, 
	aspect=2, 
	inner ysep=1em,
	left=20pt of new-case
] (problem) {\textit{Problem}};
\path[->](problem) edge (new-case);
\node [
	cloud, 
	draw,
	cloud 
	puffs=10,
	cloud puff arc=120, 
	aspect=2, 
	inner ysep=1em,
	right=20pt of solved-case
] (solution) {\textit{Solution}};
\path[->](solved-case) edge (solution);
\end{tikzpicture}



\end{document}
